I guess the comparison I'd like to see if SelfAdjointView(dense) = SelfAdjointView(dense) * SelfAdjointView(dense).
On Tue, Oct 6, 2020 at 11:38 AM David Tellenbach <[email protected]> wrote: > @Rasmus, here are some benchmarks: > https://listengine.tuxfamily.org/lists.tuxfamily.org/eigen/2018/08/msg00010.html > (scroll > the the very end). As already said, Hermitian * Hermitian can give quite > good performance and Dense * Hermitian doesn't really hurt. > > On 6. Oct 2020, at 02:26, David Tellenbach <[email protected]> > wrote: > > IIRC it was in fact you who suggested using not a plain packed but a > rectangular full packed format ;-) ( > https://software.intel.com/content/www/us/en/develop/documentation/mkl-developer-reference-c/top/lapack-routines/matrix-storage-schemes-for-lapack-routines.html#matrix-storage-schemes-for-lapack-routines_RFP_STORAGE > ) > > If this is worth definitely depends on the particular use-case. It has > been shown that a rectangular full packed format can be beneficial for e.g. > Cholesky (http://www.netlib.org/lapack/lawnspdf/lawn199.pdf > <http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.214.102&rep=rep1&type=pdf>) > or Pade approximations ( > https://pdfs.semanticscholar.org/86d2/28da4fc02672b2c990eb48a5a605c0e0360f.pdf). > I published benchmark on this list and will try to dig them out. A > Hermitian*Hermitian product can be quite fast (you can basically fall back > to gemm for blocks in the RFP format) but Dense*Hermitian was not so good > if I remember correctly. > > David > > On 6. Oct 2020, at 02:16, Rasmus Munk Larsen <[email protected]> wrote: > > David, > > I can see that this might save 50% of memory by only storing the upper or > lower triangle, and it would be nice to be able to automatically dispatch > to faster eigensolvers etc. for Hermitian matrices. However, packed storage > kernels are notoriously hard to optimize, and I wonder how much we would > gain over the existing mechanism like SelfAdjointView? > > https://eigen.tuxfamily.org/dox/classEigen_1_1SelfAdjointView.html\ > <https://eigen.tuxfamily.org/dox/classEigen_1_1SelfAdjointView.html/> > > Do you have some benchmark numbers for your patch? > > Rasmus > > On Mon, Oct 5, 2020 at 5:07 PM David Tellenbach < > [email protected]> wrote: > >> Hi Jens, >> >> It would be great if you could finish this! I just saw that the patch is >> not accessible anymore, I'll see if I can find it. >> >> Best, >> David >> >> On 4. Oct 2020, at 21:27, Jens Wehner <[email protected]> wrote: >> >> Thanks David, >> >> I would probably like to give it a shot to brush up on my template >> programming skills or lack thereof. >> >> Do you have the code somewhere public so I can have a look? If you have >> time afterwards we can have a chat about the better implementation. >> >> Cheers Jens >> >> *|* Jens Wehner, PhD *|* eScience Research Engineer *| *Email: >> [email protected] >> <https://outlook.office.com/mail/options/mail/[email protected]> >> *|* Tel: +31(0)6 438 666 87 *|* >> *|* Netherlands eScience Center <https://www.esciencecenter.nl/> *|* Science >> Park 140 *|* 1098 XG Amsterdam *| *The Netherlands *|* >> *| Twitter <https://twitter.com/eScienceCenter> | LinkedIn >> <https://www.linkedin.com/company/netherlands-escience-center> | Facebook >> <https://www.facebook.com/NLeScienceCenter/> | YouTube >> <https://www.youtube.com/channel/UCYLAIMi62d8tx3Ru6DOSPeg> | Newsletter >> <https://esciencecenter.us8.list-manage.com/subscribe/post?u=a0a563ca342f1949246a9f92f&id=31bfc2303d> >> |* >> >> >> ------------------------------ >> *From:* David Tellenbach <[email protected]> >> *Sent:* Sunday, October 4, 2020 0:16 >> *To:* [email protected] <[email protected]> >> *Subject:* Re: [eigen] Hermitian matrices >> >> Hi Jens, >> >> Yes, I've implemented support for Hermitian matrices as a Google Summer >> of Code student in 2018 and finishing it is still somewhere on my backlog. >> However, with today's knowledge the implementation should look quite >> differently. If you are interested to work on this I'm happy to discuss. >> Otherwise you will have to wait until I find some time to reimplement it. >> This won't take me too long but without committing to anything, I can >> already say that I won't find time before the beginning of 2021. >> >> Best, >> David >> >> On 2. Oct 2020, at 23:30, Jens Wehner <[email protected]> wrote: >> >> I recently discovered that David Tellenbach started/was in the >> middle/finished a >> >> Hermitian matrix class. >> http://manao.inria.fr/eigen_tmp/pullrequests/467/ >> I wanted to know what the status is and if any help is needed to push >> that along. >> >> Cheers Jens >> *|* Jens Wehner, PhD *|* eScience Research Engineer *| *Email: >> [email protected] >> <https://outlook.office.com/mail/options/mail/[email protected]> >> *|* Tel: +31(0)6 438 666 87 *|* >> *|* Netherlands eScience Center <https://www.esciencecenter.nl/> *|* Science >> Park 140 *|* 1098 XG Amsterdam *| *The Netherlands *|* >> *| Twitter <https://twitter.com/eScienceCenter> | LinkedIn >> <https://www.linkedin.com/company/netherlands-escience-center> | Facebook >> <https://www.facebook.com/NLeScienceCenter/> | YouTube >> <https://www.youtube.com/channel/UCYLAIMi62d8tx3Ru6DOSPeg> | Newsletter >> <https://esciencecenter.us8.list-manage.com/subscribe/post?u=a0a563ca342f1949246a9f92f&id=31bfc2303d> >> |* >> >> >> > >
